Slope Stability and Mass Movement

Flashcards to help study the key terms and concepts related to slope stability and mass movement.

Slope

A sloped surface on the landscape, which can be rock slopes or soil-covered slopes. (Crozier, 1986)

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Mass movement

The movement of soil and rock material down a slope due to gravity. (Crozier, 1986) - catastrophic

Shear stress

The stress component that acts parallel to the surface of a material. (Crozier, 1986)

slope falls because of stress or strength

Shear strength

The internal resistance of a material to shear stress, determined by effective normal stress and cohesion. (Crozier, 1986)

Landslide

A sudden and fast movement of a large amount of earth material down a slope. (Crozier, 1986)

Triggers of landslides

Factors such as heavy rainfall, earthquakes, or human activities that can initiate a landslide. (Crozier, 1986)

Tectonic activity

Geological processes associated with the movement of the Earth's lithosphere, often associated with landslides in active regions.

Creep

The slow, gradual movement of soil or rock down a slope. (Crozier, 1986)

Pore pressure

Pressure exerted by water within the pores of soil or rock, affecting slope stability. (Crozier, 1986)

Coulomb-Terzaghi equation

An equation used to calculate shear strength of a slope based on normal stress and cohesion. (Crozier, 1986)

Effects of gravity on slopes

Gravity pushing down on an object

when balance changes between forces - land moves

Stable slope

Normal force is greater than shear stress

Conditionally unstable slope

Normal force is equal to or greater than shear stress

Actively unstable slope

slope is failing

threshold provides a set of conditions

Water content

particles stick together

more water - slope falls more quickly

Slope materials and structure

• (Kirkby, 2005)

  

application to geomorphological hazards

 

Measuring shear stress

Factors affecting slope stability

(Kirkby, 2005)

Factors to consider

Preparatory factors and triggers

Continued

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Case study: North Norfolk Coast

 

Geographic clues to mass movement

Case study: Nepal

 

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